Electrical plugs are used to connect electrical devices with electrical sockets. There are several issues that may arise in the use of these plug/socket combinations. As shown in FIG. 1, an operator 1 may attempt to remove the plug 3 from the socket by grasping the electrical cord 5 attached to the plug 3 and pulling on the cord 5 rather than properly grasping the plug 3. As shown in FIG. 2, this may cause the plug 3 to rotate in the socket and cause damage to the terminals 2 that result in increased electrical resistance and resulting in higher terminal temperatures in use or could cause a terminal to facture. This is particularly true of plugs conforming to the National Electrical Manufacturers Association (NEMA) 5-15P standard connected within sockets conforming to the NEMA 5-15S standard. These plugs have two blade style terminals (neutral and hot) that are aligned with the direction of rotation and one round pin terminal (ground). The blade terminals can easily rotate within their rectangular sockets, but the round terminal is constrained within its round socket and is more likely to bend or break.
Similar rotation of the plug 3 in the socket may also be caused by an electrical device 6, such as an electric vehicle battery charger, also known as electric vehicle service equipment (EVSE), hanging from an outlet 7 where the socket 8 is oriented such that the cord exits the top of the plug and then curves outwardly to extend to the EVSE as shown in FIG. 3.
Although this problem of plug rotation may more acutely affect angled plugs 3 having a 90 degree cord 5 to terminal 2 relationship as in the plugs shown in FIGS. 1-3, a straight plug 9 having a 180 degree relationship between the terminals 2 and the cord 5 as shown in FIG. 4 may also experience rotation in the socket that could damage the plug terminals if the cord or plug is pulled or yanked in an upward or downward direction.
Therefore, a needs exists for an electrical plug designed to inhibit damage to plug terminals caused by rotation of the plug terminals in the socket.
The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions.